I am befuddled by this. I've done plenty of sorting in Js, but for some reason I'm getting strange behavior.
x = [{ts: "2013-09-24 14:44:22"}, {ts: "2013-09-24 14:08:26"}, {ts: "2013-09-24 17:37:42"}].sort(function(a,b) {return a.ts < b.ts;});
console.log(x); // this is sorted
But, when I use a longer array, the sort doesn't work. Just look at the first three objects of the second sort:
Any ideas?
Your comparator needs to return a number, not a boolean.
A negative number if less than, 0 if equal, a positive number if greater than.
.sort(function(a,b) {
if(a.ts == b.ts) return 0;
return a.ts < b.ts ? -1 : 1;
});
Try changing your sort function:
.sort(function(a,b) {
if(a.ts < b.ts) return -1;
else if(a.ts > b.ts) return 1;
return 0;
});
Sort it as dates, that is what you want :
y.sort(function(a,b) {
return new Date(a.ts) < new Date(b.ts);
});
forked fiddle http://jsfiddle.net/bHh4g/
Has accidently removed console.log(y); in the fiddle, but reinserted it will show it now sorts correct.
Finally
It turns out FireFox / Safari Date() doesnt like dates on the form "2013-09-24 14:44:22"
they need y/m/d instead :
y.sort(function(a,b) {
var d1 = a.ts.replace(/-/g,'/');
var d2 = b.ts.replace(/-/g,'/');
d1 = new Date(d1);
d2 = new Date(d2);
return (d1 < d2) ? -1 : (d1 > d2) ? 1 : 0;
});
console.log(y);
forked fiddle http://jsfiddle.net/Jnx4w/
works in both Chrome / FF.
Two things: your sort function should return a signed number, not a boolean, and it looks like you want to compare dates, not strings.
For your sort function, try:
function(a,b){ return (new Date(a)).getTime() - (new Date(b)).getTime();}
You compare string... no timestamp ;)
y = y.sort(function(a,b) {
var ta = (+new Date(a.ts));
var tb = (+new Date(b.ts));
if (ta < tb)
return -1;
if (ta > tb)
return 1;
return 0;
});
sortmodifies the original array and returns a boolean....sort(function(a,b) { return b.ts.localeCompare(a.ts); });.sort()returns the original Array.